Pointing devices are widely used to support human-computer interaction. Current pointing devices allow the user to move an on-screen cursor using movements of their arm and wrist (e.g. in the case of computer mouse devices) or their fingers and thumb (e.g. in the case of touch-pads and trackballs). Most users prefer mouse devices for regular use on a desktop setting. Mouse devices are generally considered to be more comfortable for extended use than other alternatives.
The traditional computer mouse detects two-dimensional motion relative to the surface upon which it is placed, and includes one or more buttons for binary input (known as ‘clicking’). Since its inception in the 1960s, the computer mouse has undergone several decades of iterative refinement. For example, mouse devices now offer high fidelity sensing of a user's movement due to high-resolution optical sensors that can be used to track displacement over many types of surface. The basic mouse functionality has also been augmented with additional capabilities, the most successful of which has been the addition of the scroll wheel. Modern mouse devices are ergonomically designed to be held in a single hand and require little effort to use. Such refinements have resulted in the computer mouse becoming a very well-established device for desktop users. Nevertheless, the basic mouse concept and functionality has remained essentially unchanged.
Humans are naturally dexterous and use their fingers and thumbs to perform a variety of complex interactions with everyday objects to a high precision. Certain input movements and gestures are more easily accomplished by using the fine motor control of one or more fingers and thumb, rather than the gross motor control of the arm and wrist. For example, moving an object a fraction of a millimeter, or tracing an accurate path (for example, when drawing or writing) can be more quickly, easily and exactly accomplished by using fingers and thumb rather than with the arm and wrist. The traditional computer mouse design, however, makes little use of this dexterity, reducing our hands to a single cursor on the screen. Our fingers are often relegated to performing relatively simple actions such as clicking the buttons or rolling the scroll wheel.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known pointing devices.